In the infection therapy, the processes of identifying infecting bacteria, rapidly measuring sensitivity of a patient against antibiotics, and determining an antibiotic to make a treatment plan, are important for the appropriate antibiotics treatment.
In a general procedure, the following flow is performed including the processes of: applying a submitted sample to a culture medium and cultivating bacteria; preparing a bacterial suspension by picking up bacterial colonies thus formed and suspending the bacterial colonies in saline or the like; and inoculating the bacterial colonies with a measurement device of an identification/drug sensitivity test apparatus. In the identification/drug sensitivity test, it is essential to accurately and reproducibly have the bacterial amount inoculated with the measurement device kept constant in the predetermined concentration so as to obtain accurate results.
In many cases, in order to obtain a predetermined bacterial amount, the following procedure is performed including the steps of: picking up a colony by selecting a same species of multiple bacterial colonies from the bacterial colonies grown-up in a petri dish; suspending the selected bacterial colonies in a liquid such as saline, in a single vessel; and measuring turbidity or clouding of the liquid, thereby to prepare a suspension with a predetermined bacterial concentration (or the predetermined number of bacteria).
Herein, the species of the bacterial colonies to be mixed have to be the same. However, multiple species of bacterial colonies generally have grown in the same petri dish. This may demand a high level of a technique for a laboratory technician to select the same species of bacterial colonies from the multiple species thereof. Further, the selection of the multiple bacterial colonies from a variety of large and small colony sizes may require an addition of the bacterial colonies or saline for dilution so as to prepare a test liquid with the predetermined turbidity, even after a test liquid has been once prepared. When the addition of the bacterial colonies is needed, it is necessary to put the sample in the incubator again and wait for the growth of the bacteria, resulting in the requirement of a complicated operation and time. Moreover, those processes are needed to be conducted in large amounts at a large-scale hospital or the like, which leads to a strong demand for an automation apparatus and procedure.
For example, the patent document 1 discloses an apparatus for recognizing positions of bacterial colonies on a petri dish. The apparatus is basically comprised of an automatic recognition unit for recognizing positions of bacterial colonies by using a CCD camera or the like. Then, based on the positional recognition, a tool for collecting bacterial colonies, controlled by an XYZ motor, collects the bacterial colonies. This enables the apparatus to recognize spatial positions of the cultivated bacterial colonies on the petri dish, resulting in the automatic collection of the bacterial colonies by operating a colony collecting pin.
Further, in a bacterial colonies classification, a bacterial colony counter or the like is provided, performing computer processing of feature quantities including color data such as brightness and saturation, and shape or outline data such as degree of an area and a perfect circle, from the image of the individual bacterial colonies, thereby to calculate respective values of the feature quantities. Then, the bacterial colony counter classifies the bacterial colonies depending on the respective values and displays the classified bacterial colonies. Such an apparatus uses a method for having each feature quantity individually specified, as a procedure that a laboratory technician adjusts the classified results shown by the computer.